A. Methyltransferases performing the steps of de novo DNA methylation, H3K36 and H3K27 methylation.
B. An example of repressed chromatin mediated by the PRC2 and PRC1 complexes, as initiated by PRC2 recruitment to unmethylated CpG islands (CGIs) and consequent spread of H3K27 methylation, and followed by chromatin compaction by canonical PRC1 which recognizes H3K27me3 through its CBX subunit.
C. An example of active chromatin, illustrated by co-regulation of intergenic domains by H3K36me2- and H3K27ac-depositing enzymes, whereas genic deposition of H3K36me3 recruits various readers with distinct functions.